org.apache.flink.runtime.state

Interface TaskStateManager

All Superinterfaces:

CheckpointListener

All Known Implementing Classes:

TaskStateManagerImpl

public interface TaskStateManager
extends CheckpointListener

This interface provides methods to report and retrieve state for a task.

When a checkpoint or savepoint is triggered on a task, it will create snapshots for all stream operator instances it owns. All operator snapshots from the task are then reported via this interface. A typical implementation will dispatch and forward the reported state information to interested parties such as the checkpoint coordinator or a local state store.

This interface also offers the complementary method that provides access to previously saved state of operator instances in the task for restore purposes.

Method Summary

Modifier and Type	Method and Description
LocalRecoveryConfig	createLocalRecoveryConfig() Returns the configuration for local recovery, i.e.
PrioritizedOperatorSubtaskState	prioritizedOperatorState(OperatorID operatorID) Returns means to restore previously reported state of an operator running in the owning task.
void	reportTaskStateSnapshots(CheckpointMetaData checkpointMetaData, CheckpointMetrics checkpointMetrics, TaskStateSnapshot acknowledgedState, TaskStateSnapshot localState) Report the state snapshots for the operator instances running in the owning task.

Methods inherited from interface org.apache.flink.runtime.state.CheckpointListener

notifyCheckpointComplete

Method Detail

reportTaskStateSnapshots

void reportTaskStateSnapshots(@Nonnull
                              CheckpointMetaData checkpointMetaData,
                              @Nonnull
                              CheckpointMetrics checkpointMetrics,
                              @Nullable
                              TaskStateSnapshot acknowledgedState,
                              @Nullable
                              TaskStateSnapshot localState)

Report the state snapshots for the operator instances running in the owning task.

Parameters:

checkpointMetaData - meta data from the checkpoint request.

checkpointMetrics - task level metrics for the checkpoint.

acknowledgedState - the reported states to acknowledge to the job manager.

localState - the reported states for local recovery.

prioritizedOperatorState

@Nonnull
PrioritizedOperatorSubtaskState prioritizedOperatorState(OperatorID operatorID)

Returns means to restore previously reported state of an operator running in the owning task.

Parameters:

operatorID - the id of the operator for which we request state.

Returns:

Previous state for the operator. The previous state can be empty if the operator had no previous state.

createLocalRecoveryConfig

@Nonnull
LocalRecoveryConfig createLocalRecoveryConfig()

Returns the configuration for local recovery, i.e. the base directories for all file-based local state of the owning subtask and the general mode for local recovery.